The invention relates to an insertion catheter for inserting a vascular prosthesis into a vessel, with an elongate, substantially tubular catheter cover having a proximal and a distal end, with an outlet for the vascular prosthesis provided at the distal end.
Vascular supports, i.e., so-called stents or stent grafts comprising metallic supporting structures which may also be covered with fabric are presently in use for treating vascular occlusions in humans, in particular, in the peripheral area of the human body, or also for eliminating abdominal and thoracic aortic aneurysms. These supporting structures are placed endoluminally by means of a catheter in the affected vascular segment.
The stents or stent grafts are mounted in a compressed, unexpanded state on the catheter and may be surrounded by a protective tubular cover which prior to insertion of the implant is retracted in order to release the latter. The vascular support assumes its final shape either by way of self-expansion owing to its plastic supporting structure or by being mounted on a balloon which transfers the vascular support into its opened shape by way of forced expansion.
Such supporting structures have the drawback that owing to an interaction between the metallic support and the fabric cover under dynamic stress the cover may suffer damage and cause endoleakages to occur.
To prevent such wear, vascular prostheses may also be used without any metallic or other supporting structure. These have the additional advantage that in vessels with low flow rates additional obstructions in the form of supporting structures do not act to cause occlusions. In particular, thin-walled prostheses are used with advantage and these are fitted with a balloon to the prepared vessel wall. In the case of such vascular prostheses having no supporting structure there is, however, the danger that when inserting these a section thereof will become twisted and result in closure of the vascular prosthesis. A safe and defined insertion of such vascular prostheses cannot be fully guaranteed with insertion catheters of the kind described at the outset.
The object of the present invention is, therefore, to so design an insertion catheter of the kind described at the outset that a vascular prosthesis can be inserted in a particularly simple and safe way into a vessel of the human body without causing closure of the vascular prosthesis by, for example, twisting.